Kirk, Go into the bilge and put your hand on the transducer. You should feel it thump. If not it is probably the transducer if it is getting power. Need to check that first. What is on the display? If all dashes then no info is coming from the transducer. If it is blank it can be a number of things including a bad LCD. Airmar made your transducer and odds are pretty good they still make it. Call them and discuss it, they are very helpful.

Call Gemeco (Airmar) @ 843-210-7000. They just helped me isolate the problem with a similar problem.

In my case, I'd get an "Depth Sounder not connected" message. Gemeco told me to check if my water temp was working properly. I checked it and it was behaving very erratically. Gemeco told me if the head unit doesn't get a good reading from the temp sensor, it doesn't look any further for the depth sounder. I replaced the transducer and all is fine.